The present invention relates to a vehicle seat, and more particularly to an integrated seat frame and restraint assembly for a reclining vehicle seat where the restraint assembly is secured to the seat frame, and the seat frame includes cooperating struts to limit forward rotation of the seat back during a sudden deceleration or accident.
Vehicle seat designs include a wide variety of seat belt systems to help safely restrain an occupant in the event of a sudden stop or accident. The seat and restraint system should address a variety of design factors such as passenger comfort, ease of use, and safety during a sudden deceleration or impact. Federal Motor Vehicle Safety Standards (FMVSS) have been developed to help minimize the possibility of the failure of seat and restraint designs by the forces acting on them as a result of a vehicle impact. The weight of the seats and the fuel efficiency of the vehicle are also concerns of modem vehicle designs. Seat and restraint assemblies should be relatively compact and easily integrated into a variety of cabin dimensions and floor and wall construction so that the seat and restraint assembly can be installed in a variety of vehicles. Practical considerations such as cost and serviceability are also a part of the design criteria. Successful seat designs address each of these factors.
Many conventional vehicle seats anchor the seat belts directly to the floor or walls of the vehicle. These belt assemblies reduce the loads exerted on the seat and its frame so that the seat can remain relatively light in weight. Unfortunately, these nonintegrated seat and restraint designs can be impractical for adjustable seats that comfortably accommodate the passenger. Adjustably mounted seats can slide forward and back and can include a reclining seat back that allows the seat to comfortably accommodate a variety of passengers. Adjustable seats also allow each passenger to periodically adjust the seat to shift their body position to reduce fatigue. Seat belt assemblies anchored to the floor or wall of the vehicle are not readily adapted for use with these types of seats. Reclining seats are particularly problematic because lengthening or shortening the shoulder belt will not readily compensate for the fixed anchor point of the belt relative to the various recline positions of the seat. Seats with separate restraint systems are also more difficult to incorporate into the cabins of a wide variety of vehicle types. The floor and wall structures of the vehicle may not accommodate the desired anchor points for the lap and shoulder belts.
Some vehicle seat designs anchor the lap and shoulder belt to the seat frame. This typically involves securing or routing the shoulder belt over the upper end of the seat back. While these seat and seat belt systems are more readily adapted for adjustable seats with slide rails and reclining seat backs, the frame of the seat must be robustly designed to withstand the loads imparted on the vehicle seat by the momentum of the seat and its occupant during a rapid deceleration or accident. For example, FMVSS 571.207 entitled Seating Systems and 571.210 entitled Seat Belt Assembly Anchorages require a seat and seat belt assembly to withstand forces in excess of 3,000 pounds. Conventional lightweight recline mechanisms are not capable of withstanding these loads. Reclining seats and recline mechanism designs that meet these safety standards are usually bulky and prohibitively expensive because they require large, heavy components, or components made of exotic materials.
The seat and restraint system must also be comfortable and easy to use in order to be well received by the industry. The seat frame and restraint system should not inhibit or render it awkward or uncomfortable to move into or out of the seat. The front of the seat cushion should be free of rigid obstructions, particularly for truck seat designs. Truck seats are typically mounted on and elevated by a pedestal so that the legs of the occupant tend to press against the front of the seat cushion. In addition, the shoulder belt should not chafe the neck of the occupant, or cinch across the upper torso of the occupant.
The present invention is intended to solve these and other problems.
The present invention pertains to a vehicle seat with an integrated frame and restraint assembly that is particularly suited for a truck. The seat frame assembly includes a seat frame mounted to a slide rail pedestal anchored to the vehicle floor, and a back frame joined to the seat frame. The frame has a lightweight construction and includes a conventional recline assembly for maintaining the seat back in one of a variety of recline positions. The restraint assembly has a continuous lap and shoulder belt that is directly secured to the seat frame at both its ends. The seat frame has a pair of upwardly extending struts with rearward facing angled surfaces. The back frame has a pair of forwardly extending struts with forward facing angled surfaces. The angled surfaces flushly engage each other when the seat is in an upright position. Should the recline mechanism fail during a sudden deceleration or accident, the forward rotation of the back frame will stop at its upright position.
One advantage of the present vehicle seat invention is its combined comfort and strength. The seat can recline for comfort during normal operation, yet is strong enough to maintain its integrity during a sudden forward deceleration or accident. The integrated restraint assembly has a continuous lap and shoulder belt that is firmly secured to the seat frame to help safely restrain the occupant. Each side of the frame assembly includes one set of cooperating struts. These two sets of struts prevent the forward rotation of the seat back should the lock assembly of the recline mechanism fail during a front-end collision. The struts provide added rigidity to the frame and stop the forward rotation of the back frame beyond its upright position. Tests indicate that the present seat frame and belt assembly maintains its integrity when loads or forces of over 3,900 pounds are imparted on the back frame. Accordingly, the present seat frame and restraint assembly should meet or exceeds current safety standards.
Another advantage of the present seat frame and belt assembly is its lightweight construction and economical materials. The seat frame components are made of strong, durable steel that is readily available and manufactured at relatively low cost. The seat frame and its struts are formed by hollow tubular components reinforced by stiffening plates to produce a compact and lightweight seat frame. The design also incorporates a conventional lightweight recline and locking mechanism. The struts allow the lock mechanism of the recline assembly to fail during a simulated 20G deceleration, such as those required by the FMVSS tests. Thus, the present invention is able to use a lightweight seat frame assembly with a conventional lightweight recline and lock mechanism to achieve a fuel efficient seat frame and restraint assembly while meeting FMVSS requirements.
A further advantage of the present seat frame and belt assembly is its simplicity and compact design. The two sets of triangular shaped struts allow the seat design to maintain standard height and width dimensions so that the seat will easily fit into the cabin of most commercial trucks. The seat is equipped with a conventional recline and lock mechanism so these components do not pose any unusual installation problems. The shoulder belt is looped through a D-ring toward the top of the seat back frame, and is received and anchored by a conventional lightweight retractor at the rear of the seat frame. Bulky and complicated frame assemblies and recline and locking mechanisms are avoided. The result is a compact seat frame and restraint assembly with an attractive appearance that is easily incorporated into the relatively tight space requirements of a wide variety of vehicles.
A still further advantage of the present seat and restraint assembly is its comfort, easy of use and attractive appearance. The seat frame and restraint system is easily negotiated by an occupant when he or she enters or exits the seat. The struts extend less than two inches above the seat frame and four inches forward from the back frame platforms upon which the seat cushion and back cushions are placed. The seat and back cushions extend beyond all or a majority of the struts so they do not detract from the seats appearance. The small distance the struts extend from the seat and back platforms do not obstruct the person from entering or exiting the seat. The triangular shaped struts taper at an angle of about 10 degrees toward the front end of the seat frame and top end of the back frame. The front of the seat frame is free of obstructions. The tapered seat struts do not tend to interfere with or inconvenience people when they rest on and compress the side of the seat cushion as they enter or exit the seat. The tapered back struts do not interfere or inconvenience the arm movements of people when they are sitting in the seat. In addition the shoulder belt is oriented so that it will not chafe the neck of the occupant or cinch across the upper torso of the occupant.
Other aspects and advantages of the invention will become apparent upon making reference to the specification, claims and drawings.